Location Services (LCS) provided by or in association with wireless networks can be useful or essential to many applications—for example to locate a user engaged in an emergency call, to obtain navigation (e.g. driving directions), to locate nearby friends or facilities and to track valuable objects and assets.
The Long Term Evolution (LTE) wireless access interface is a standard in the mobile phone network technology tree, developed by the 3rd Generation Partnership Project (3GPP), that also produced the Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA) network technologies. The LTE Positioning Protocol (LPP) is the protocol defined by 3GPP to support LCS in a wireless network based on LTE with capabilities to locate a User Equipment (UE). LPP extensions (LPPe) is a positioning protocol developed by the Open Mobile Alliance (OMA) that extends LPP to support location for access types in addition to LTE as well as adding further position methods applicable to both LTE and other wireless access types such as GSM, UMTS and WiFi. LPP may be used by itself in an LTE network or may be combined with LPPe to support LCS in LTE and/or other networks. In the latter case, the combined protocol may be referred to as LPP/LPPe.
Current 3GPP defined technology uses point-to-point positioning protocols such as LPP and LPP/LPPe to support LCS. The use of point-to-point protocols may result in significant signaling and processing requirements on both the network and UEs and difficulty in providing adequate location support for all UEs accessing a network. Furthermore, while delivery of LCS Assistance Data via broadcast has been standardized for GSM and UMTS access, it has not been deployed. One reason for this is additional implementation impact—e.g. to network base stations, Location Servers and UEs. A second reason is that the broadcast Assistance Data standards are based on an old 3GPP Release (Release 98 completed in 1999) and do not contain any Assistance Data enhancements defined since then. A third reason is that some broadcast systems, such as those already defined to support GSM and UMTS broadcast location Assistance Data, have limited bandwidth and cannot broadcast large amounts of Assistance Data (e.g. GNSS (Global Navigation Satellite System) ephemeris data) with a low latency. However, broadcast location Assistance Data remains potentially useful to avoid the overhead and delay in obtaining assistance data by point to point means (e.g. using LPP or LPP/LPPe). The problem is to define it in a manner that would be suitable for implementation and with adequate performance for receiving devices.